Archive for the ‘Hardware’ Category

New Table Design

When I first started this blog I had little idea how Multi-Touch worked, and what was practical and within bounds of readily available technology.  I originally intended to make a large(40 Inch) Rear-Projection DI Table, which through many mistakes and decisions, has now turned into a rear-projection LLP Table.  Unfortunately, my projector bulb recently died, killing this table, and as of current I have a front LLP setup on uding old 17 Inch monitor.  This setup, while it does work pretty well, has some major disadvantages.  The lasers have to be pointing away from the camera(so they don’t appear as blobs), thus illumination can only come from one side.  This causes really bad occlusions, making Multi-User interaction nearly impossible(aside from that fact that it is on a 17 Inch 5:4 monitor).

I came across the LumenLab database of monitors a few days ago, and my 17 Inch Monitor(Samsung 712N) was on the list of those that didn’t have FCC Issues, so I figured I would give it a go at taking it apart and mounting the camera behind it.  If it turns out to work well I might make a nice box for it.

Taking apart this monitor was amazing, and I _HIGHLY_ recommend it for anyone trying to find a small monitor to take apart for such a project.  It is amazing how high quality and easy to take apart it was built, its almost like they took us into consideration when they designed it!  Ill post a more details description with pictures later(once I take some:)).

I got my Aixiz Lasers working!

For those of you that have been keeping up with my blog, you would probably know that I ordered some Lasers from Aixiz, but have not gotten them to work.  Well, I was about to send them back, when I noticed a NUIgroup Member names AixiZ.  He said there was some misinformation about the voltages, and said they were 5v devices and not 3.2v.  Well, I found a 5v wall wart, cut off the end, hooked them up to a breadboard, and they work!  I am going to try and get them lined up so my setup will actually work, so in the meantime, some pics:

There are the 10mW 780nm Lasers from Aixiz.

I got a projector(+ Image warping)!

I was searching around Craigslist for a broken projector(read: working projector with dead bulb) so I could hack a different bulb into it, and not pay $400 for a $6 bulb.  I found one, a Proxima DP6850.  Its a really nice projector, 1024×768(1280×1024 max), Digital Keystoning and Zoom, two RGB inputs, S-Video, and built in speakers.  The only places it lacks are brightness(1500 lumens) and Bulb Life(1500 Hours).  Bulb life didn’t really matter to me, and I figured it would probably be brighter if I go sticking a huge metal halide bulb in there.  It is circa-2000, and retailed for $8500.  The Craigslist seller wanted $75 for it, so I figured I really had nothing to lose, and if it didn’t work at all at least I would end up with a lot of good lenses and LCD filters.

I bought it this morning, only to arrive home and find out the bulb works!  I don’t know how much longer it will last, so I am going to wait until I am ready to mount it in my table to play with it(excluding the image warping).

A while ago I saw that openFrameworks demo where he uses openGl shaders to warp a playing video onto a white board.  I could not find the code anywhere, so I used “The GIMP” to Perspective Transform an image.  I achieved the same effect, and was able to get a picture of the earth onto a piece of paper.  Video below: